Aberrant imprinting in humans: Application of genomewide approaches to better understand imprinting regulation and its disturbances

人类异常印记：应用全基因组方法更好地了解印记调控及其干扰

• 批准号: 497659591
• 负责人: Professor Dr. Thomas Eggermann, Ph.D.
• 金额: --
• 依托单位: Institut für Humangenetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/497659591?language=en
• 关键词: Aberrant; imprinting; humans; Application; genomewide

Imprinting disorders (ImpDis) comprise congenital diseases which are characterised by disturbances of parentally imprinted genes. These genes are expressed either from the paternal or the maternal allele, and the disturbances consists of both genomic and epigenetic alterations. The clinical diagnosis of ImpDis is often hampered by the lack of clinical specifity, as the symptoms can overlap. ImpDis are caused by four different molecular changes: Three of them represent classical molecular changes, but epimutations comprise DNA modifications (e.g. 5-methylcytosine). The causes of epimutations are unknown in the majority of cases, but molecular alterations in imprinted regions themselves (cis factors) as well as in other genomic regions (trans factors) probably play a role. However, systematic approaches are currently missing, due to technical limitations as well as the rareness of ImpDis. With the implementation of NextGenerationSequencing and Longread-Sequencing techniques suitable assays are now available fort he comprehensive analyses of genomic, structural, epigenetic and transcriptional factors of epigenetic regulation and ist disturbances. This proposal combines second and third generation sequencing approaches with a unique cohort of patients with 11p15.5 and 14q32 epimutations to address genomic and epigenetic variations at allelic resolution in protein and nonprotein coding regions. The strategy to identify the molecular basis of ImpDis includes (a) Genome-wide analysis of methylation in carriers of 11p15.5 and 14q32 epimutations to identify multilocus imprinting disturbances (MLID) and to discriminate ImpDis subgroups. (b) Identification of genomic variants in cis and trans factors causing both MLID and isolated epimutations. (c) Determination of allele-specific methylation patterns on single molecule level over long distance covering whole differentially methylated regions at once. (d) Characterization of large structural variants to identify new regulating elements. Altogether, we aim to identify factors and functional genomic regions which regulate genomic imprinting and the expression of imprinted genes. We will both determine epigenomewide patterns of aberrant methylation as well as chromosomal regions and factors involved in the regulation of imprinting in the same assays. The analysis will not be restricted to specific genomic regions but the proposal will cover whole genomes of both the patients and their parents. In combination with transcriptome data functional consequences of disturbed imprinting can be delineated. This approach will help to understand the pathoetiology of ImpDis, but it will also be translationally used for clinical management of the patients.

印迹疾病包括以父母印迹基因紊乱为特征的先天性疾病。这些基因要么来自父系等位基因，要么来自母系等位基因，这些干扰包括基因组和表观遗传改变。由于症状可能重叠，临床诊断常常因缺乏临床特异性而受到阻碍。impdi是由四种不同的分子变化引起的：其中三种代表经典的分子变化，但突变包括DNA修饰（例如5-甲基胞嘧啶）。在大多数情况下，变异的原因尚不清楚，但印迹区域本身的分子改变（顺式因子）以及其他基因组区域的分子改变（反式因子）可能起作用。然而，由于技术限制以及对impdi的认识不足，目前缺乏系统的方法。随着NextGenerationSequencing和long - read- sequencing技术的实施，现在可以使用合适的检测方法来全面分析表观遗传调控和序列干扰的基因组，结构，表观遗传和转录因素。本研究将第二代和第三代测序方法与11p15.5和14q32表观变异患者的独特队列相结合，以解决蛋白质和非蛋白质编码区等位基因分辨率的基因组和表观遗传变异。鉴定ImpDis分子基础的策略包括(a)对11p15.5和14q32基因突变载体的甲基化进行全基因组分析，以鉴定多位点印迹干扰（multilocus imprinting disorders， MLID）并区分ImpDis亚群。(b)查明导致MLID和孤立的变异的顺式和反式因素的基因组变异。(c)在单分子水平上测定长距离覆盖整个差异甲基化区域的等位基因特异性甲基化模式。(d)描述大型结构变异以确定新的调节因素。总之，我们的目标是确定调节基因组印迹和印迹基因表达的因素和功能基因组区域。我们将在相同的分析中确定异常甲基化的表观基因组模式以及参与印迹调节的染色体区域和因素。该分析不会局限于特定的基因组区域，但该提议将涵盖患者及其父母的整个基因组。结合转录组数据，可以描述干扰印迹的功能后果。这种方法将有助于了解ImpDis的病理机制，但它也将转化用于患者的临床管理。